A lesson from a saboteur: high molecular weight kininogen (HMWK) impact in COVID‐19

Colarusso, Chiara; Terlizzi, Michela; Pinto, Aldo; Sorrentino, Rosalinda

Severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) is a newly identified coronavirus which has spread from China to the rest of the world causing the pandemic coronavirus disease 19 (COVID‐19). It has fatality rate that floats from 5 to 15% and the symptoms are fever, cough, myalgia and/or fatigue up to dyspnea, responsible for hospitalization and in most of the cases of artificial oxygenation. In the attempt to understand how the virus spreads and how to pharmacologically abolish it, it was highlighted that SARS‐CoV‐2 infects human cells by means of angiotensin converting enzyme 2 (ACE2), transmembrane protease serine 2 (TMPRSS2) and SARS‐CoV‐2 main protease (M(pro)). Once bound to its receptor ACE2, the other two proteases, in concert with the receptor‐mediated signaling, allow virus replication and spread throughout the body. Our attention has been focused on the role of ACE2 in that its blockade by the virus increases Bradykinin and its metabolites, well known to facilitate inflammation in the lung (responsible for cough and fever), facilitate both the coagulation and complement system, three mechanisms that are typical of angioedema, cardiovascular dysfunction and sepsis, pathologies which symptoms occur in COVID‐19 patients. Thus, we propose to pharmacologically block the kallikrein‐kinin system upstream bradykinin and the ensuing inflammation, coagulation and complement activation by means of lanadelumab, which is a clinically approved drug for hereditary angioedema.